Valve for rock drills



May 29, 1928. 1,671,431

E. a. LEAR VALVE FOR ROCK DRILLS Filed April 7, 1 927 f MD - Fig -1. c

. a INVENTOR. H 2 12' all? ear. i BY ms ATT RNEY.

Patented May as, teas.

EARL BLLEAR, or rrrrnrrrsnuns, NEW

JERSEY, ASSIGNOR T ING-ERSOLL-RALID COMPANY, JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

VALVE FOR BOOK DRILL-S,

Application filed April 7,

This invention'relates tofrock drills, but more particularly to a distributing valve for fluid actuated rock drills of the hammer 7 type. I f v The objects of the invention are to obtain a light-weight valve capable of rapid re ciprocation, to simplify the construction and reduce the cost of manufacturing valves of this type.

10 Other objects will appear hereinafter, and v to all of these ends the invention consists of the combination of elements, features of construction and arrangement of parts substantially as hereinafter described and claimed and illustrated in the accompanying drawings, in whichv Figural is a longitudinal sectional elevation of a portion of a rock drill showing the valve in position for admitting pressure fluid into the rearward end of the cylinder,

and v v i Figure 2 is a view similar to Figurel showing the valve in position for admitting pressure fluid into the front end of the cylinderQ i Referring to the drawings, the invention is shown embodied in a rock drill having a cylinderA in which is disposed a reciprocatory hammer piston The piston B has; a

forwardly extending nose 0 cooperating slidably with a front cylinder washer D which forms a closure for the front-end of the cylinder A. A closure is provided for the rearward end of the cylinder A in the form of a back head E in WhlCh'lS disposed a throttle valve F for controlling the admission of pressure fluid from a source of supply (not shown) to a passageG in the back head E. 7

On one side of the cylinder A and preferably extending longitudinally thereof as illustrated, is a valve chest Hhaving an annular recess J i which extends from. the rearwardend of the valve chest H to a point vI) 'G for admitting 1927. Serial no. 181,730. 7

In this Way the bushing P is held against movement in a forwardly direction and by forming the end of the bushing P flush with the rearward endof the valve chest H, said bushing may alsobe held against movement in a rearwardly direction bythe back' head E which extendssacross' the rearward end of the valve chest.

Any suitable means, such as the usual side bolts (not shown), may be provided for 4' clamping the back head E securely to" the cylinder A.

As will be observed, the inner end of the bushing P terminates at a point'adjacent an exhaust port'Q in. thel'valve chest H. On the opposite side of the'exhaust port is disposed another bushing R which abuts with its front end'thewall'K. The bushings P and R have bores S and T respectively,

.andiat the inner or adjacent ends of these I bores are formed enlarged recesses. Uwhich, together with the bores S and T, form a valve chamber V for o distributing valve W;

The distributing valve is of the hollow type, that is, it has a longitudinal bore X which extends throughout the length of the 'valve and the ends of the bore X in this instance cooperate slidably with plugs Y and Z. The plug Y extendsthrough the bushing P whereby it is also supported and has a passage Z) which registerswiththepassage 1 pressure fluid into the bore X of the valve.

In this instance pressure fluid is conveyed intermittently through ports Y from the interiorof the plugY to the rearward end of the valve chamber V to act against'the rearward end of the valve for holding the valve firmly in its extreme forwardmost posit-ion. In order to enable the escape of pressure fluid thus utilized for holding the valve, the valve chest H and the bushing P are provided with a vent o leading to the atmoshere. y l

which extends into the front end of the valve W and has a reduced threaded extension 0 which projects through the wall K to rece1ve a nut The plug Z comprises-a body portion d f whereby the plug- Z may be drawn p firml against the bushing R and the bushing firmly against the wall K. The plug Z also serves to convey pressure fluid to the front end of the valve chamber V for hold ing the valve temporarily in its rearwardmost position. To this end the said plug is provided. with a passage g from which radiate passages h for conveying pressure fluid to the front end of the valve chamber. At this end-- of the valve chamber is also formed a vent 0' for exhausting the pressurefluid utilized for holding the valve rearwardly.

the cylinder.

Preferably near the rearward end of the valve W are formed ports y1which,.when the valve is in its forwardmost position or when thevalve is approaching this position, will register with an inlet. passage 7: leading from thevazlvechamber V to the rearward end of the cylinder A. The front end of the valve is likewise provided. with similar ports '0- Intermediate the. ends of the valve W is formed-an. enlarged flange g which cooperates slidably with the recesses U and has rearward and. forward actuating surfaces 1* and, 's. respectively against which pressure fluid may act for actuating the valve from one extreme position to, the other. Such pressure; fluid in this instance is conveyed from the cylinder to therearward recess U through. a kicker passage '25 crossed with re- "spect toa kicker passage a leading from'the cylinder, at a' point rearwardly of a free exhaust port 4; to the forward recess U. The kicker passage'u, conveys. pressure fluid from the cylinder to act against the front actuating surface s for throwing the valve rearwardly. Both the kicker passages u and t, as well asvt-he'free exhaust port '0, are in this instance controlled by the piston B.

' The operation of the device is as follows: With the: valve and piston in the positions shown inFigure 1' pressure fluid entering the bore X of. the valve will pass through the ports j and? the inlet passage to the rearward end of the cylinder to move the piston B. forwardly. The valve will remain in this position until the kicker passage u is uncovered by the piston, whereupon pressure fluid will, flow into the front recess U and, acting, againstthe actuating surface s, will move the-valve rearwardly to the position shown in. Figure 2; However, while the valve is in its forewardmost position, the

ports Y are also uncovered by the valve, so that pressure fluid may flow into the valve chamber to act against the rearward end of the valve for holding the valve immovably in its extreme forwardmost position. Obviously the pressure fluid. acting against the rearward end of the valve will be somewhat lower than line pressure as this end of the valve is constantly open to atmosphere. This, however, will result only in-a reduction in pressure as thevent c is of such-cross sectional area that there willbe a sufficient pressure acting against the valve to hold it against trembling.

Assuming now' that the valve is in the position illustrated in Figure 2,, pressure fluid will flow through the ports 0,.the inlet passage p into the front end of the cylinder to return the piston. In this position ofthe valve the ports X will be covered by-the rearward end of the valve and the ports I in the plug Z will be uncovered by the front end of the valve to admit pressure fluid into the front end of the valve chamber holding the valve V in itsrearwardmost position. Upon the admission of pressure fluidJinto the recessU of the bushing P the valve W willagain be actuated forwardly, thus completing the cycleof operations,

As will be observed, the flange g in/addition to providing actuating surfaces for throwing the valve also controls the exhaust port Q and after the valve has been actuated a sufiicient distance to uncover the ports Y or it, as the case may be, the pressure fluid utilized for throwing the valve will be immediately exhausted to the atmosphere through the exhaust port Q. j

I claim: I

1. In a fluid actuated rock drill, the' combination of a cylinder and Piston, a valve chest having a valve chamber, inletpassages leading from the valve chamber to the ends of the-cylinder, a hollow valve in the valve chamber constantly exposed interiorly to live pressure fluid, said valve having ports. to register with the inlet passages, a flange'ion the valve intermittently exposed atits ends to live pressure fluid from the cylinder for actuating the valve,- recessed plugs cooperating slidably with the valve,.and passages to live pressure fluid from the cylinder for valve chamber to the atmosphere for exactuating the valve, plugs cooperating slidhausting the pressure fluid untilized for ably with the valve, passages inthe plugs holding the valve. i admitting pressure fluid into the ends of the In testimony whereof I have signed this 5 valve chamber for holding the valve during specification.

the admission of pressure fluid to the cylinv I der, and vents leading from the ends 01 the I EARL B. LEAR. 

